Stable isotope tracers have become invaluable tools with which to investigate human metabolism. This laboratory has been involved in the application and development of stable isotope tracer methods for the past 20 years. New kinetic models and analytical approaches have been developed in this lab to investigate various aspects of glucose, fat and protein metabolism. The specific goal of this core laboratory is to make available mass spectrometry analysis for all projects involved with the Burn Center. We have all the equipment necessary to perform stable isotope enrichment measurements, including five quadrupole gas chromatograph mass spectrometers, a gas chromatography-combustion- isotope ratio mass spectrometer, an isotope ratio mass spectrometer interfaced to an elemental analyzer, and an inductively coupled plasma mass spectrometer. We also have the necessary expertise to trouble shoot and develop new analytical procedures. Our expertise in mathematical modeling will be central to the interpretation of resulting enrichment data. Training and education are also an aspect of the mass spec core activity.